Electrophysiological and behavioral responses of female African rice gall midge, Orseolia oryzivora Harris and Gagné, to host plant volatiles

Abstract

African rice gall midge, Orseolia oryzivora Harris and Gagné, is a major pest of rice in Africa. Depsite its economic importance, its chemical ecology is not well understood. Here, we assessed behavioral and electrophysiological responses of O. oryzivora to host plant volatiles. In olfactometer bioassays, mated female O. oryzivora were attracted to volatiles emitted from intact rice plants but were repelled by volatiles collected from plants infested by conspecifics. In a choice test, there was a preference for volatiles from uninfested plants over those from infested plants. Coupled gas chromatography-electroantennography analyses of panicle volatiles isolated four electrophysiologically active components: (S)-linalool, 4,8-dimethyl-1,3,7-nonatriene, (E)-caryophyllene, and (R/S)-(E)-nerolidol. A synthetic blend of volatiles at the same concentration and ratio as that from an intact plant was attractive to mated females, whereas a blend based on the ratio of volatiles from an infested plant was repellent. This suggests that O. oryzivora uses olfaction for host plant recognition. The identification of blends of volatiles emitted by plants that can both attract and repel O. oryzivora may aid the development of sustainable control measures.

Recent advances in allelopathy for weed control: from knowledge to applications

“…Homoterpenes (monoterpenes with an added methylene group) have also been studied as allelochemicals . These terpenoids can arise via different biosynthetic routes in a tissue‐specific manner; in the case of 4,8‐dimethyl‐1,3,7‐nonatriene, it is synthesized by degradation of the C30 triterpene diol, arabidiol, and catalyzed by the Brassicaceae‐specific cytochrome P450 monooxygenase CYP705A1 …”

“…81 Homoterpenes (monoterpenes with an added methylene group) have also been studied as allelochemicals. 82 These terpenoids can arise via different biosynthetic routes in a tissue-specific manner; in the case of 4,8-dimethyl-1,3,7-nonatriene, it is synthesized by degradation of the C30 triterpene diol, arabidiol, and catalyzed by the Brassicaceae-specific cytochrome P450 monooxygenase CYP705A1. 83,84 Allelopathy studies can be used to discover new monoterpenes, such as (−)-(1R*,2S*,4R*,5S*)-3,3-dimethyl-5-hydroxybicyclo[2,2,1] hept-2-ylmethanol isolated from Eupatorium adenophorum, which inhibited Arabidopsis thaliana seed germination by 20%.…”

Terpenes and Terpenoids in Plants: Interactions with Environment and Insects

“…It was found that less damage was caused by Paropsisterna tigrina adults in Melalecua alternifolia , in the presence of a high concentration of terpinolene [ 59 ]. In addition, volatiles containing the same terpenoids present in intact and infested rice plants attract or repel the rice pest Orseolia oryzivora depending on their concentrations [ 60 ] Table 2 summarizes examples from relevant studies.…”

The Galling Truth: Limited Knowledge of Gall-Associated Volatiles in Multitrophic Interactions

“…Female orange wheat blossom cecidomyiid midges Sitodiplosis mosellana were attracted by key compounds, e.g., ( Z )-3-hexenyl acetate, acetophenone, and 3-carene, present in minor proportions in the overall volatile profile of wheat panicles ( Birkett et al, 2004 ). The African rice gall cecidomyiid midge Orseolia oryzivora preferred volatiles from uninfested plants while those from infested plants served as repellents; the major difference between these volatile profiles was a considerable increase in the HIPV ( E )-β-caryophyllene ( Ogah et al, 2017 ).…”